1. Field of the Invention
The present invention relates to an apparatus for judging a target to be temperature-regulated among targets to be temperature-regulated having a different pressure loss when a fluid is supplied from a fluid supply source to the target to be temperature-regulated, e.g., a process chamber used for manufacturing of semiconductor wafers.
2. Description of the Related Art
The semiconductor manufacturing apparatus is provided with a process chamber. A fluid is used to regulate the temperature in the process chamber, and the process chamber is provided with a flow path for flowing the temperature regulating fluid.
FIG. 8 is a diagram showing a conventional fluid supply route.
When an electric motor 8 is activated, a fluid accumulated in a tank 7 is sucked by a pump 3 and discharged to a pipeline 1. The fluid discharged to the pipeline 1 is temperature-regulated by a heat exchanger unit 6 and supplied to a flow path of a process chamber 21. The fluid is flown through the flow path of the process chamber 21 and discharged to the tank 7 via a pipeline 2. Thus, the fluid is circulated through the tank 7 and the process chamber 21.
In the process chamber 21, a semiconductor wafer (hereinafter referred to as the wafer) is processed. Generally, a thermal capacity is large as the wafer has a larger diameter. Therefore, a large flow rate is necessary for the wafer having a larger diameter to obtain a desired target temperature by the process chamber 21. Therefore, the process chamber 21 for processing a large-diameter wafer is configured to have the flow path with a large diameter so as to flow the fluid at a flow rate corresponding to the large-diameter wafer. The process chamber 21 for processing a small-diameter wafer is provided with a flow path having a small diameter to flow the fluid at a flow rate corresponding to the small-diameter wafer. Thus, the process chamber 21 has a different structure for each diameter of the wafers to be processed. Because the process chamber 21 has a different structure, the flow rate of the fluid to be supplied to the process chamber 21, namely a target flow rate, is also different. Therefore, it is necessary to regulate the temperature of the fluid after controlling the flow rate to a target flow rate corresponding to the process chamber 21.
Conventional flow rate control is generally performed by two following methods. One of them uses an inverter to control the rotation speed of the pump, and the other adjusts a closing degree of a manual valve which is disposed on a pipeline. Thus, the flow rate control is performed by a worker who judges the process chamber 21 and operates a changeover switch and the manual valve to adjust the flow rate of the fluid.
Japanese Patent Laid-Open Publication No. 2004-169933 discloses a system which controls an inverter by a controller to control the rotation speed of the pump to adjust a flow rate of the fluid supplied to a process chamber.
The conventional flow rate control requires the judgment of a process chamber by a worker and the operation by the worker. Therefore, there is a high possibility of an operation error by the worker. The possibility of an operation error becomes higher if the worker is not well experienced. To prevent the operation error, it is necessary to establish an operation procedure, to perform through training of workers and the like, and considerable labor and costs are involved. Even if the described methods are adopted, it is impossible to completely eliminate the operation error even if it is possible to decrease the occurrence of the operation error.
To eliminate the operation error, a system which controls a flow rate by an apparatus, e.g., the system disclosed in Japanese Patent Laid-Open Publication No. 2004-169933, may be configured to control the flow rate automatically. To perform the flow rate control full automatically, it is also necessary to perform judgment of the process chamber automatically before the flow rate control. But, there was no existing technology to judge the process chamber.
The present invention has been made in view of the above circumstances and makes it possible to automatically judge a target to be temperature-regulated and to eliminate a setting error of a target flow rate.